在虛擬機上增加硬盤

1、先將虛擬機Power Off，在Virtual Machine Setting對話框裏點擊左下角的“Add”，選擇“Hard Disk”，之後選擇“Create a new virtual disk”，分配容量，其他默認配置就可以了。
2、啓動虛擬機系統，用root登陸，利用 # ls /dev/sd*  的命令可以看到最後有一個sdb 或sdc（如果是添加的第三塊硬盤會是sdc），它沒有sdb1和sdb2或sdc1和sdc2之類的設備文件，說明系統檢查出來了這塊硬盤但還沒有分區格式化。這樣就是上一步添加的硬盤。
在命令行用fdisk -l查看是否識別了新硬盤，如果添加的是IDE硬盤，就應該看到hdb，如果是SCSI硬盤，看到的就應該是sdb。
Disk /dev/sdc: 1073 MB, 1073741824 bytes
255 heads, 63 sectors/track, 130 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk identifier: 0x00000000
Disk /dev/sdc doesn't contain a valid partition table
因爲我之前已經加過一塊硬盤了，所以這裏顯示sdc。
3、使用fdisk /dev/sdc，
然後輸入類似如下的參數：
n （add a new partition）
p （建立主分區）    1（第一個分區）    1（第一個柱面） 1024（最後一個柱面）
w （保存）
選擇好這些選項中選擇“w”，即將分區表寫入硬盤並退出，這時再用fdisk -l查看就會發現：
Disk /dev/sdc: 1073 MB, 1073741824 bytes
255 heads, 63 sectors/track, 130 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk identifier: 0x5404b953
Device Boot Start End Blocks Id System
4、用mkfs命令將其格式化，mkfs.ext3  /dev/sdc1
5、建立一個要把新硬盤mount到得目錄，比如建立一個 /work
再用mount命令將其掛載，mount -t ext3 /dev/sdc1 /work
6、最後，修改/etc/fstab文件，把要mount的新硬盤追加到後面，如下：
vi /etc/fstab
/dev/sdc1 /work ext3 defaults 1 2
==================================================================
附錄：/etc/fstab文件解析
1. fstab文件的作用
文件/etc/fstab存放的是系統中的文件系統信息。當正確的設置了該文件，則可以通過"mount /directoryname"命
令來加載一個文件系統，每種文件系統都對應一個獨立的行，每行中的字段都有空格或tab鍵分開。同時
fsck、mount、umount的等命令都利用該程序。
2. fstab文件格式
下面是/etc/fatab文件的一個示例行：
fs_spec fs_file fs_type fs_options fs_dump fs_pass
/dev/hda1 / ext2 defaults 1 1
fs_spec - 該字段定義希望加載的文件系統所在的設備或遠程文件系統，對於一般的本地塊設備情況來
說：IDE設備一般描述爲/dev/hdaXN，X是IDE設備通道(a, b, or c)，N代表分區號；SCSI設備一描述
爲/dev/sdaXN。對於NFS情況，格式一般爲:
,例如：`knuth.aeb.nl:/。對於procfs，使用`proc來定義。
fs_file - 該字段描述希望的文件系統加載的目錄點，對於swap設備，該字段爲none；對於加載目錄名包
含空格的情況，用40來表示空格。
fs_type - 定義了該設備上的文件系統，一般常見的文件類型爲ext2 (Linux設備的常用文件類型)、
vfat(Windows系統的fat32格式)、NTFS、iso9600等。
fs_options - 指定加載該設備的文件系統是需要使用的特定參數選項，多個參數是由逗號分隔開來。
對於大多數系統使用"defaults"就可以滿足需要。其他常見的選項包括：
選項含義
ro 以只讀模式加載該文件系統
sync 不對該設備的寫操作進行緩衝處理，這可以防止在非正常關機時情況下破壞文件系統，但是卻降低了
計算機速度
user 允許普通用戶加載該文件系統
quota 強制在該文件系統上進行磁盤定額限制
noauto 不再使用mount －a命令（例如系統啓動時）加載該文件系統
fs_dump - 該選項被"dump"命令使用來檢查一個文件系統應該以多快頻率進行轉儲，若不需要轉儲就設
置該字段爲0
fs_pass - 該字段被fsck命令用來決定在啓動時需要被掃描的文件系統的順序，根文件系統"/"對應該字
段的值應該爲1，其他文件系統應該爲2。若該文件系統無需在啓動時掃描則設置該字段爲0
3. 示例文件
# /etc/fstab
/dev/hda9 swap swap defaults 0 0
/dev/hda1 / ext2 defaults 1 1
/dev/hda5 /home ext2 defaults 1 1
/dev/hda6 /usr ext2 defaults 1 1
/dev/hda7 /usr/local ext2 defaults 1 1
/dev/hda8 /var ext2 defaults 1 1
/dev/hdb /cdrom iso9660 noauto,user 0 0
none /proc proc defaults 0 0
none /dev/pts devpts gid=5,mode=620 0 0
=======================================================================
具體操作例子如下：

I’ve been using
VMWare
for a while now and I always get asked some common questions about it.
One of those is how to add a new virtual disk to a Linux virtual
machine. So in response to that, here are the steps to adding a new
SCSI based virtual disk to a CentOS Linux virtual machine. The steps
for adding a disk to a 視窗系統 machine is very much the same except you
would use the Disk Management utility from the Control Panel.
Step 1: Open virtual machine settings
Select your virtual machine, as you can see from the photo I selected
the Infrastructure virtual machine. Next press the “Edit virtual
machine settings’ to open the Virtual Machine Settings dialog.

Step 2: Add new hardware
From the “Virtual Machine Settings” dialog select the “Add…” button at
the bottom of the screen. From this dialog you can also modify how much
memory you dedicate to the machine when it boots.

Step 4: Select new hard disk
From this screen we can see the many types of hardware we can add to a
virtual machine. You can emulate just about any piece of hardware that
one can expect in a modern operating system. It definitely makes
testing with different configurations and devices much easier. For our
example we want to select “Hard Disk” and then select the “Next >”
button.

Step 5: Create the virtual disk
In the next screen we see the three options for adding a new disk. We
can “Create a new virtual disk”, this will create a brand new disk on
the guest operating system. The second option, “Use an existing virtual
disk”, allows you to mount a disk from another virtual machine. I like
to do this with my “source” drive. I have one virtual disk that I’ve
made that has all the Oracle and Linux CDs on it, that way I can just
mount it to the machine I need when I have to do a new install instead
of copying the binaries I need across disks, its definitely a big time
saver. The last option is to “Use a physical disk”, this allows you to
mount a local physical disk to the operating system. This option is
akin to NFS mounting a drive to a virtual machine. To add a new disk we
select the “Create a new virtual disk” option and select the “Next
>” button.

Step 6: Select type of disk
Next we want to select the type of disk. I’ve been using VMWare for a
long time and agree that the recommended Virtual Disk Type should be
SCSI. I don’t know why, but I’ve had much better success with the SCSI
virtual disks than the IDE ones. So in this step we want to select
“SCSI (Recommended)” and the “Next >” button.

Step 7: Set disk size and options
Now we want to set the size of the disk we are creating. One of the
nice features of VMWare is that you don’t have to allocate all of the
disk when you create it. So if you create a 40 GB disk it doesn’t have
to take it all right away, the disk will grow as your virtual machine
needs it. I will say this is a big performance hit you take when the
disk has to extend, but for most applications its OK. Also, I will warn
that if the virtual disk grows and there is no physical disk left on
the host operating system you will see a catastrophic failure and in
most cases both the host and guest operating systems lock up and become
unusable. (Don’t say I didn’t warn you) Lastly, you can split the files
into 2GB sizes, while this isn’t necessary, it just makes all the disks
much easier to manage and move around. For this step we want to set our
disk size (12 GB in this case), I chose not to allocate the disk space
right now (the machine has a 300 GB drive and has only 20 GB on it) and
Split disk into 2 GB files.

Step 8: Name the disk file
This is actually pretty simple in that you decide what you want to
physically call the disk and where to put it. .vmdk is the extension
for VMWare virtual disks. After we name the disk we can select the
“Finish” button which adds the disk to the virtual machine.

Step 9: Ensure new disk exists
So now we can see that the new disk has been added to the “Virtual
Machine Settings” within the selected virtual machine. From here the
disk acts just like it would if you added a new disk to a standalone
server. So we select the “OK” button to continue.

Step 10: Boot the virtual machine
From here we just start the virtual machine like we would normally,
either by selecting the button on the toolbar or selecting the “Start
this virtual machine” link.

Step 11: Virtual machine start up
The machine boots normally as it would any other time.

Step 12: Create the Partition
After we’ve logged in and accessed a terminal window as root (or
another user with root/sudo privs) we first want to run fdisk on the
newly created drive. In Linux the first SCSI drive is sda, the second
sdb, the third sdc, etc. since this was the second SCSI drive we added
to the system, the device is known as /dev/sdb
The first command we want to run is fdisk /dev/sdb (NOTE: Thanks to everyone that caught my typo here)
this utility works very much like the DOS utility of the old days and
allows you to create and manage partitions. To create a new partition
we enter the command n to create a new partition.  This is going to be a primary partition p, and the first partition number 1.
Because I want this disk to consume the full 12 GB I specified earlier
we start at the first cylinder and end it at the last cylinder. We then
want to write the partition table with the new partition we have just
created so we enter the command w which writes the new table and exits fdisk.

Step 13: Format the partition
Now that we’ve create the partition, we now want to format the first
with the new file system. I’ve decided to use ext3 filesystem for this
disk, ext3 provides all the features of the classic ext2 file system
plus journaling which helps to prevent disk corruption in the event of
an improper shutdown and speeds up the recovery process. For a good
overview of Linux standard file systems check out this article:
http://linux.org.mt/article/filesystems
So, to format the new partition we enter the command mkfs -t ext3 /dev/sdb1.  This command makes a new files system with the type t ext3 on the /dev/sdb1 partition, this is the first partition on the sdb disk.

Step 14: Create the mount point
Determine where you want to add the new virtual disk you’ve created. I
like to create a partition specifically for all the software I install
after the basic Linux install called /software to do that we run mkdir /software,
just a simple make directory command. Once that is complete we then
want to mount the newly created partition. Because we haven’t added the
partition to the /etc/fstab yet we have to mount it manually.  To do that we run mount -t ext3 /dev/sdb1 /software.
To break down this command we run mount with the ext3 filesystem type,
the partition /dev/sdb1 to the directory /software. Pretty simple and
straight forward. To check that the partition is properly mounted we
run df -k which shows us the mounted partitions and the amount of available space.

Step 15: Open the fstab file
The fstab file holds all of the used disks and partitions, and
determines how they are supposed to be used by the operating system. So
we edit the file to add the newly created partition

Step 16: Modify the fstab for the new partition
After we open the fstab file in the previous step we add the following line:
/dev/sdb1                      /software                      ext3    defaults                1 1
The first column is the partition name, the second is the default mount
point, the third is the filesystem type. The fourth is the mount
options, in this case I used default which mounts the drive rw, suid,
dev, exec, auto, nouser and asynchronous. The 5th and 6th options are
for the dump and fsck options. If dump is set to 1 the filesystem is
marked to be backed up, if you are going to have sensitive material on
the drive its a good idea to set it to 1. If fsck is set to greater
than 1, then the operating system uses the number to determine in what
order fsck should be run during start up. If it is set to 0 it will be
ignored such as in the case of a cdrom drive since its a solid state
disk. For more information on the fstab file check out this article:
http://www.tuxfiles.org/linuxhelp/fstab.html
Lastly, we write and quit the file with the :wq command.

So now that the fstab has been written the drive will be mounted and
unmounted when the machine is either started or shutdown. So there you
have it, the quick and dirty process for adding a brand new disk to a
virtual machine. Until next time…